Self-drilling and self-tapping miniscrews for osteosynthesis fixture after LeFort I osteotomy: An ex vivo trial for primary stability and a randomized clinical study.

BACKGROUND: Self-drilling osteosynthesis screws (SDS) have a potential higher primary stability together with clinical advantages such as less time effort compared to self-tapping screws (STS). The aims of the study were to compare the primary stability of SDS and STS ex vivo and to analyze of the time-saving effect in vivo. MATERIALS AND METHODS: Ex vivo, both screws were placed in porcine bone. Torque was measured for insertion and removal. Four specimens were kept in bone for histologic bone-to-implant-contact examination. In vivo, 49 patients who received orthognathic surgery in the maxilla were included in 2 centers. In a split-mouth design, the time for osteosynthesis fixation and perioperative events were recorded. RESULTS: Ex vivo, insertion and removal torque measurements were higher for SDS, especially in dense bone. Histologic imaging on the exemplary-stained specimens showed higher bone contact and compressed bone matrix for SDS in all bone densities. In vivo, the mean osteosynthesis time in both centers was 5.5 min (±3.03) for SDS and 5.5 min (±2.37) for STS. Separate analysis showed that center I was faster with STS and center II with SDS. Although, in center I a higher rate of failed primary stability of SDS compared to STS was documented. CONCLUSIONS: SDS showed a partially higher primary stability ex vivo, especially in dense bone. The timesaving effect of SDS is less pronounced than expected, but technically SDS might be favorable where drilling is difficult or even impossible.

Multifocal metastasizing extra-ocular facial sebaceous carcinoma as diagnostic challenge: case report and systematic review.

PURPOSE: Sebaceous carcinoma (SC) is a rare adnexal tumor. Extra-ocular, facial SC is very uncommon and local metastases are an extreme rare finding. A respective case is presented and discussed together with the current literature. CASE AND REVIEW: A tumor of the left ear of an 87-old male was primary excised together with multiple suspicious lesions of the head and neck. Most specimens were histopathologically rated as squamous cell carcinomas (SCC). Despite the in-sano resection, additional new suspicious retro-auricular and temporal lesions were detected. Successive resections were diagnosed as basal cell carcinomas (BCC) and, because of a non-in-sano resection in a third approach, as SC. After reappraisal and immunhistochemical staining [epithelial membrane antigen (EMA), CK 5-6 and CD 15], most of the former specimens turned out to be SC as well. A literature search showed 3 reported cases of extra-ocular head and neck SC with cutaneous local metastases. In another review, in a total of 168 cases, SC was diagnosed after wrong initial histological diagnosis (SCC n = 56, BCC n = 44; other entity or precursors of carcinomas n = 68). CONCLUSION: Due to inconsistent histologic patterns, histopathological misdiagnosis of the uncommon facial SC and its metastases may complicate further therapy, prolong treatment and may lead to a worse prognosis of this neoplasm. A close interdisciplinary collaboration of clinician, surgeon and pathologist is of most relevance for the right diagnosis.